The present disclosure relates generally to a wound care bandaging system and, more particularly, to a system and method for the treatment of leg ulcers. The system and method of the present disclosure may advantageously be used in the treatment of venous stasis ulcers, e.g., caused by venous valve insufficiency, venous wall damage, and so forth, and will be described herein primarily by way of reference thereto. However, it will be recognized that the present bandaging system will also find utility in the treatment of edema, eczema, ulcers, and other wounds or sores of the lower extremities having various origins.
It is well known in the art to apply a dressing known as an “Unna boot” or alternatively “Unna's boot” for the treatment of venous stasis ulcers and other venous insufficiencies of the leg. An Unna boot is a gauze bandage, typically a 3-4 inch wide woven cotton gauze or scrim coated with a medicated zinc paste, sometimes referred to as “Unna's paste,” which comprises zinc oxide in a carrier of glycerin and/or gelatin, and may also contain other ingredients such as calamine (e.g., zinc oxide, zinc carbonate, or zinc silicate, colored with ferric oxide), methyl paraben, propyl paraben, acacia, castor oil, white petrolatum, ichthammol, and so forth. Unna boots were brought to market in 1904, one hundred and eight years ago, and have remained essentially unchanged. Unna boot bandages are currently widely commercially available from a variety of manufacturers and distributors, including BSN Medical, Inc., Bayer Pharmaceuticals Corporation, Covidien AG, and others.
In use, the Unna boot is typically applied by wrapping the paste-impregnated gauze under light tension in spiral, overlapping turns starting at the base of the toes and stopping 1-2 inches below the knee. The gauze is typically covered with an outer layer such as an elastic or cohesive bandage, dry gauze, tubular bandage, stocking or sock which may be provided to provide additional compression to the leg as well as to protect the paste bandage and to keep the patient's clothing clean. Unna boots can sometimes be left on for up to 7 days before changing. However, because the prior art Unna boot cannot absorb a large volume of fluid, frequent changing is required when applied to large, severe, and/or heavily draining ulcers, for example, when drainage from the wound starts to leak from the Unna boot dressing.
Commonly, absorbent pads (e.g., formed of cotton or cotton/wool batting material) are applied to the inside of the impregnated gauze layer covering the area of the ulcer to absorb excess exudate. However, even with absorbent pads, seepage of the wound exudate throughout the wrap is common. Exudate, which resembles blood plasma in composition, contains a variety of substances including inflammatory mediators and protein-digesting enzymes, among other things, which can have a damaging effect on both the wound being treated as well as healthy skin that is otherwise undamaged by the wound or ulcer being treated.
In addition, the presence of one or more additional absorbent layers increases the time required to apply the bandage system. It also decreases patient comfort because the additional thickness makes such three (or more) layer systems more difficult to wear under clothing and footwear and causes the uncomfortable buildup of body heat and moisture under the bandages. The additional time to apply such prior art bandage systems, the increased thickness of such three or more layered systems, and the increased patient discomfort, in turn, reduce patient compliance.
Another drawback of the prior art Unna boot resides in the inability to provide a uniform coating of the zinc oxide paste on the woven gauze. As can be seen in FIG. 6 and FIGS. 11A-11D, the prior art gauze has some areas where the paste is heavily applied and other areas where the paste is extremely thinly applied. Given the inability of the woven gauze materials to hold a consistent uniformity of paste, the portion of the gauze dressing that contacts the skin being treated will often lack an adequate amount of the zinc oxide paste. The lack of uniformity of the medicated paste can also result in a lack of paste in the region of the wound being treated and/or excess paste in regions of healthy skin where it is not needed. Because the gauze layer is applied by overlapping consecutive turns of the dressing, e.g., by about 50-75%, it is possible to achieve an overall appearance of uniformity. However, such appearance of uniformity occurs as a result of multiple overlapping layers. For example, the Unna boot gauze dressing is typically applied using a simple, overlapping spiral technique, e.g., using a 50-75% overlap on adjacent turns. In such cases, only 25-50% of each turn contacts the patient's skin. Given the highly random and splotchy coverage of the Unna paste in the prior art Unna boot gauze dressings, much of the Unna paste giving the appearance of uniform coverage is actually separated from the patient's skin by one or more layers of the dressing, where it will not be delivered to the affected skin area of the wound being treated.
The present disclosure provides a new and greatly improved wound care bandage system and method which overcome the above-referenced problems and others.